Nipper mechanism for textile combing machines

ABSTRACT

THE TOP NIPPER IS PIVOTALLY MOUNTED ON THE BOTTOM NIPPER AND IS CLOSED ON THE BOTTOM NIPPER BY THE ACTION OF A SPRING LOADED ROCKER ARM. THE ROCKER ARM IS PIVOTED AT ITS TWO ENDS SO THAT THE FORWARD PIVOT POINT ON THE TOP NIPPER DESCRIBES A CLOSURE CURVE BY WHICH THE NIP-   PERS ARE DECELERATED TOWARDS THEIR POINT OF CLOSURE DURING OPERATION OF THE MECHANISM.

Feb. 16, 1971 H, @CHENBERGER ETAL. 3,562,865

NIPPER MECHANISM FOR TEXTILE COMBING MACHINES Filed Sept. l2, 1968 fraz/vf 5' United States Patent O U.S. Cl. 19-227 5 Claims ABSTRACT F THE DISCLUSURE The top nipper is pivotally mounted on the bottom nipper and is closed on the bottom nipper by the action of a spring loaded rocker arm. The rocker arm is pivoted at its two ends so that the forward pivot point on the top nipper describes a closure curve by which the nippers are decelerated towards their point of closure during operation of the mechanism.

This invention relates to a nipper mechanism for a textile combing machine. More particularly, this invention relates to a nipper mechanism wherein the closing movements of the top and bottom nippers are controlled by a linkage system.

Combing machines are best operated with a large number of opening and closing movements in order to obtain a relatively high throughput. However, conventional types of combing machines for combing textile bers have had oscillating nipper mechanisms Iwhich allow only a limited number of opening and closing movements to be completed during a combing operation. That is, because of the considerable moving mass of the oscillating nippers and of the violent sudden closure at the closing point of the top and bottom nippers of the nipper mechanism, optionally mounted for rotation one above the other, the combing machines have been subjected to considerable vibration and knocking during combing above certain speeds.

In order to overcome the disadvantages of vibration and knocking in combing machines, it has been known to damp the closure of the nippers, for example, by means of a roller arranged on the top nipper which is fixed to a machine frame, or by means of rotating supports arranged at the front and rear ends of the path followed by a nipper frame. It has also been known that the closing movement of the top nipper can be limited by an adjustable stop and that closure can be cushioned by means of a spring that counteracts the closing movement mounted at that end of the path remote from the combing cylinder.

It has also been known to compensate for the moving masses of the top and bottom nippers by rotatably suspending the nippers in such a way that their respective weights are in equilibrium, and to arrest the closure of the nippers by a spring counteracting the closing movement arranged at that end of the path remote from the combing cylinder.

A known nipper mechanism which is provided with rocking nippers comprises a bottom nipper arranged on nipper arms and connected through an arm to an oscillatable drive shaft for reciprocating said bottom nipper in response to oscillation of the drive shaft and a top nipper being arranged on corresponding nipper arms being pivotably connected to the bottom nipper. In this known nipper mechanism, the closing movement is imparted to the top nipper through a spring-loaded rocker arm fixed to lCe the machine frame, the arrangement being such that the spring-loaded rocker arm is so mounted as to swing freely about the axis of the oscillating drive shaft by which it is directly supported. In this case, the rear pivot of the spring support system, as seen in the direction in `which the fleece is drawn off, coincides with the center of the nipper drive spindle in a structure known kinematically as a four-bar linkage. The front pivot of this spring support system thus describes, during reciprocation, a curve which approaches the closure point of the nippers at a comparatively large angle to the curve which corresponds to the curve described by the front pivot of the spring support system with the nippers permanently closed. As a result in these known nipper mechanisms, the top and bottom nippers when closed have developed a comparatively high speed by the time they reach the closure point, resulting in a sudden, violent closure of the nippers.

Accordingly, it is an object of the invention to provide a nipper mechanism by means of which the number of cycles of a combing machine can be increased very appreciably in relation to conventional arrangement.

It is another object of the invention to close the nippers of a combing machine in a gentle manner.

It is another object of the invention to close the nippers of a combing machine with a delayed closure movement while counterbalancing the nippers.

Briefly, the invention provides a nipper mechanism for combing machines `which includes a bottom nipper arranged on nipper arms and reciprocable with a top nipper by means of an arm fixed to an oscillating drive shaft. The top nipper is further arranged on corresponding nipper arms pivotally mounted on the bottom nipper. The closing movement of the top nipper `with respect to the bottom nipper is imparted through a spring-load rocker arm which is pivotable at two points; the rear pivot point, as seen in the direction in which a fleece is drawn off, being geometrically arranged in such a way that, during reciprocatory rocking movement, the front pivot point describes a closure curve in which the nippers are decelerated towards their point of closure.

The nipper mechanism may also have a counterbalance system that is in equilibrium both with the closing movement and with the moving mass of the nippers.

These and other objects and advantages of the invention will become more apparent from the following detailed description and appended claims taken in conjunction with the accompanying drawings in which:

FIG. l illustrates a section through a nipper mechanism according to the invention in the open position;

FIG. 2 illustrates a section through the nipper mechanism of FIG. 1 in the closed position; and

FIG. 3 diagrammatically illustrates a four-bar linkage of the nipper mechanism.

Referring to FIGS. l and 2, the nipper mechanism is arranged on both sides, i.e. to the left and right, of a top nipper 1 and bottom nipper 4. The top nipper 1 is pivotally mounted at point A by a top nipper arm 2 on a bottom nipper arm 3 of the bottom nipper 4. The bottom nipper 4 is pivotably connected at point B through an arm 5 to a crank lever 6 which in turn is fixed on an oscillatable nipper drive shaft 7. The front end of the bottom nipper is, at the front end near the tuft outlet position, pivotably connected at the point C to an arm 9 rockable about a comb segment 15 of a combing cylinder 1S arranged so as to rotate freely on a circular comb shaft 8 as known per se. A spring loaded rocker arm 10 is pivotably connected to each of the top nipper arms 2 (only one is shown) at point D. The arm 10 consists of a rod 12 pivoted at point D on the rear end of the nipper arm 2 of the top nipper 1 and at point E on a link 13 which may be in the form of a forked lever. Additionally at the point E the rod 12 is arranged slidably (not shown) in the direction of its longitudinal axis. The rod 12 is kept in its end position at the point E by an elastic pressure member 11 which is at its front end xedly mounted on the rod 12 and at its rear end supported on the link 13 pressing the rod 12 off from the link 13. Pivoted to the link 13 at point F is a crank lever 14 which in turn is fixed to the nipper drive spindle 7 in which point B represents the center. At that end of the link 13 remote from the combining cylinder 15', a counterbalance 17 is rotatably supported on the link 13 through an arm 16 at point G. The counterbalance 17 is so arranged as to pivot about the point I with its center of gravity H and is connected to the nipper drive spindle 7 through an arm 18 having a front pivot K and a rear pivot L and through a crank lever 19.

As shown, the link 13 establishes a connection between the nipper drive spindle 7 and the spring-loaded rocker arm 10 and between the top nipper 1 and the counterbalance 17. Thus, a reciprocating movement generated by the nipper drive spindle 7 through the cranks levers 14 and 6 and transmitted by means of the link 13 and arm to the nipper assembly displaces the center of gravity M of the nipper assembly (which does not coincide with the pivot D) in the opposite direction to the corresponding movement of the center of gravity H of the counterbalance 17 to which the reciprocating movement generated by the nipper drive spindle 7 is transmitted by way of the crank lever 19 and the arm 18.

Referring to FIG. 3, the nipper mechanism incorporates in addition to the structure known kinematically as a fourbar linkage, with the displaceable pivots C and B and the xed points and another structure known kinematically as a four-bar linkage with the diplaceable pivots F and G and the xed pivots and The latter fourbar linkage is connected to the rst four-bar linkage through the nipper drive spindle 7 and is in the form of a parallel crank drive, for example, consisting of the arm 16, the crank lever 14 and the link 13. When this fourbar linkage carrying the counterbalance swings back and forth, the rear pivot E of the spring-loaded rocker arm which is situated on the link 13, describes a coupling curve Kk during the reciprocation of the crank 14 and hence of the link 13. In this case of a parallel crank drive, the linking or coupling curve Kk has a circular trend. Alternatively, the coupling curve Kk generated by the reciprocation of the rear pivot E may have a trend which is governed by the choice, adapted to the circumstances prevailing, of the geometric arrangement of the rear pivot E in regard to the spindle center and the front pivot D, and may, for example, show a trend between E and In the case of the front pivot D of the spring-loaded rocker arm 10, the coupling curve of such follows a closure curve path Ks, which leads to closure of the nippers. The coupling curve Kk is thus the deciding factor in the movement of the pivot D along the path of the closure curve Ks which approaches a curve Kt which the pivot D would describe if the nippers were permanently closed, and meets the curve Kt at an intersection which is the nipper closure-point N.

On account of the front pivot point D approaching the curve Kt, point D moves at decreasing speed towards the nipper closure point N in accordance with the decreasing gradient of the closure curve Ks during reciprocation of the link 13 in accordance with the coupling curve Kk, and may then move beyond point N on the curve Kt in order, after reaching a dead position O, to return to its end position in the opposite direction via point N.

The angle at which the closure curve Ks and the curve Kt intersect towards the point N at which the nippers close, determines whether closure is violent or smooth and corresponds to the angle formed by the tangent applied to the closure curve Ks and the curve Kt at the closure 4 point N of the nippers. This angle formed by the two tangents preferably amounts to 15 at the most.

Due to the reciprocating link 13, displaceable pivot point G will move along a path P in accordance with the coupling curve Kk and since the nipper drive spindle 7 simultaneously drives the link 13 and the counterbalance 17 through the arm 18, the counterbalance 17 will be rotated about point I in an oppositely directed movement to front pivot point D and hence oppositely to the oscillation of the top nipper 1.

The aforementioned choice of the distance between E and in the four-bar linkage and the geometric arrangement of E in regard to and D is embodied, for example, in a coupling curve along which the pivot E moves in the opposite direction to the front pivot D (which follows the path of the closure curve Ks which is convex in relation to producing a closure curve Ks which approaches the intersection with the curve Kt with decreasing gradient and which is concave in relation to l.

The nipper mechanism is shown in FIG. 1 in the open position at the point of reversal corresponding to point D in FIG. 3 and thus represents one extreme of the movement of the nipper assembly swinging back and forth in equilibrium with the counterbalance 17. The nipper assembly and counterbalance 17 are at the greatest distance apart from one another and are kept in balance by way of the nipper drive spindle 7. In FIG. 2 and the nipper mechanism is shown in its closed position at the rear point of reversal corresponding to point O in FIG. 3, and thus represents another extreme of the movement of the nipper assembly swinging back and forth in equilibrium with the counterbalance 17. Nipper assembly, and counterbalance 17 are at the narrowest distance apart from one another and are kept in balance by way of the nipper drive spindle 7. Another extreme of the movement of the nipper assembly swinging back and forth in equilibrium with the counterbalance 7 is shown in FIG. 3 in which the position of the top nipper at the closure point N and the corresponding position of the counterbalance 17 are shown in chain lines.

The requirements mentioned above for obtaining large number of cycles are ideally satised by the novel closure curve KS produced by the coupling curve Kk on which point D reciprocates and by which a more gentle closure of the nippers is obtained, and by the counterbalance 17 which is connected with the nipper assembly by the link 13 and which keeps it in equilibrium, in other words the machine does not vibrate or rock with large numbers of cycles.

What is claimed is:

1. A nipper mechanism for textile combing machines comprising an oscillatable drive shaft;

bottom nipper arms having a bottom nipper thereon;

first means securing said bottom nipper arms to said drive shaft for reciprocating said bottom nipper in response to oscillation of said drive shaft;

top nipper arms pivotably connected to said bottom nipper arms and including a top nipper at one end for reciprocation with said bottom nipper;

a spring-loaded rocker arm pivotably connected at one end to said top nipper arms;

link means connected to said drive shaft for oscillation therewith and pivotably connected to the opposite end of said spring-loaded rocker arm; and

a counterbalance for the moving mass of said nippers connected to said link means whereby during reciprocatory rocking movement the arrangement of the rocker arm with said link means connected with said counterbalance allows the pivot point of said rocker arm with said top nipper arms to move on a closure curve by which said nippers are decelerated towards each other upon closure and said nippers close in a gentle manner.

2. A nipper mechanism as set forth in claim 1 wherein said counter-balance is in equilibrium with the moving mass of said nippers, and wherein said link means comprises a link, an arm pivotably connected to said counterbalance and said link, a second arm pivotably connected to said counterbalance at one end, and a crank lever mounted on said drive shaft and pivotably connected to the opposite end of said second arm in a four-bar linkage arrangement.

3. A nipper mechanism as set forth in claim 1 or 2 wherein the pivot point of said rocker arm on said link means is geometrically offset relative to the center of said drive shaft to move in a convex linking curve path with respect to said center upon reciprocation of said link means whereby the pivot point of said rocker arm with said top nipper arms moves in a concave closure curve path with respect to said center in opposition to said pivot point on said link means.

4. A nippel mechanism as set forth in claim 3 wherein said closure curve path extends to a closure point of said 6 nippers with decreasing gradient upon closing of said nippers.

S. A nipper mechanism as set forth in claim 4 wherein said closure curve path extends to said closure point at an angle of at most 15 formed by the tangents applied to said closure curve path and the curve which said pivot point of said top nipper arms would follow with said nippers permanently closed at the closure point.

References Cited UNITED STATES PATENTS 712,222 10/1902 Wenning et al. 19-235 2,005,001 6/ 1935 Nasmith 19-227 3,066,360 12/1962 Naegeli 19--227 FOREIGN PATENTS 887,468 1/ 1962 Great Britain 19-227 270,797 12/ 1950 Switzerland 19-225 896,231 5/1962 Great Britain.

DORSEY NEWTON, Primary Examiner 

